A typical screen printer is the commercially available ASP-24 automated screen printer available from MPM Corp., 10 Forge Park, Franklin, Mass. 02038, incorporated herein by reference.
A prior art screen printer includes a camera that looks between the board and the screen, reciprocating to view the board on the screen by physically rotating a viewing mechanism such as a mirror tube at the end of a video probe. Such a device is described in U.S. Pat. Application No. 07/116,490, incorporated herein by reference. Illumination of the circuit board to be viewed is accomplished by a pair of fiber optic light sources which run parallel to the video probe to provide a low angle of incidence lighting of the circuit board, thereby reducing reflected glare from the highly reflective circuit board traces into the video probe. The low angle of incidence lighting is accomplished by surrounding the video probe viewing port with a light disperser, thereby creating an illuminated planar surface with a hole disposed in it to accommodate the viewing port.
It is an important object of this invention to provide improved apparatus for illuminating and viewing an object, to be repeatedly acted upon at one or more points by a device, and the device.